PURPOSE: To automatically perform the replacement of a probe pin.

CONSTITUTION: A plurality of probe holders 25, 26 are attached to a holder stand 13 and moved up and down by a cylinder 36. Chuck release holes 31 are formed to the chuck release plate 14 moved up and down by a cylinder 36. The holder stand 13 is raised and a probe pin 27 is inserted in the probe holders 26. The chuck release plate 14 is raised to detach the probe pin 27 from a chuck unit 28 and the holder stand 13 and the chuck release plate 14 are allowed to fall and the probe pin 27 is separated from the chuck unit 28. The chuck unit 28 is aligned with a newly used probe pin 29 and the chuck release plate 14 is raised to release the lock of the chuck unit 28. The holder stand 13 is raised to insert the probe pin 29 in the chuck unit 28 and, after the chuck release plate 14 is allowed to fall, the holder stand 13 is allowed to fall.